Herbal Medicines and Women's Health

British Pharmaceutical Conference 2005

Elizabeth M Williamson

Scope of talk

General overview of the most important herbs used by women (excluding those covered earlier in more detail), where available for self-medication or to purchase OTC

Assessment of evidence available Any problems reported or anticipated when

taken with conventional drugs

Issues of particular importance to women – and not always for health reasons!

Hormonal: premenstrual syndrome (PMS), dysmenorrhoea, menorrhagia

Menopausal symptoms, including osteoporosis Child-birth, pregnancy and lactation Life-style: stress, memory loss (which may be

linked with hormonal changes) Appearance: weight-loss, cosmetic issues (again

linked to causes above)

Herbs used in hormonal conditions

PMS: evening primrose oil, St John’s wort, agnus castus

Dysmenorrhoea: dong quai, raspberry leaf, cramp bark

Menorrhagia (refer to GP or specialist): agnus castus, horsetail etc. Check iron levels.

Menopause: phytoestrogens, black cohosh, agnus castus, dong quai, St John’s wort (for depression), sage (for flushing and sweating)

Herbs and products: for PMS, menorrhagia and menopause

Herbs used during pregnancy and lactation

Pregnancy; for morning sickness: ginger* Late pregnancy; to prepare for child-birth:

raspberry leaf*Lactation; to enhance: shatavari (wild

asparagus*), agnus castus, fennel, fenugreek

Lactation; to suppress: sage, peppermint*will be further discussed

Herbs and products:pregnancy and lactation

Herbs used to treat varicose veins

To increase venous tone and strengthen blood vessels: horse-chestnut*, butcher’s broom*

To promote blood flow: red vine leaf*, bilberry, ginkgo, yarrow and hawthorn

To soothe itching: topically applied calendula, witch hazel etc

Herbs and products: varicose veins

                                                                                                                   

                         

                                                                                                                   

                         

Herbs used to slow memory loss!

General memory and cognition enhancement: sage*, lemon balm*, ginkgo*

Shown to help in post-menopausal memory problems: soya*, ginseng*, ginkgo*

Herbs and products: memory and cognition

Life-style issues: weight loss

Boldo: traditionally used – no mechanism of action postulated

Kelp: to ‘speed up’ metabolism and provide nutrients (e.g. iodine)

Ephedra*: for appetite suppression and to speed up metabolism

‘Detox’ mixtures

Herbs and products: ‘helping’ with weight loss

Herbs ‘suitable’ for self-medication?

Women usually look after the health needs of the family

Many herbal products are purchased OTC, as opposed to consulting a general practitioner, pharmacist or medical herbalist

Pharmacist ideally placed to advise… …..if they know about herbal medicines! NB: medical herbalists use many more on an

individual basis

A closer look at some of these

Some work!Some don’t!….and some are dangerous….

Pregnancy: ginger (Zingiber officinalis) for morning sickness?

Contains: gingerols and shogaols (phenolics) Evidence for efficacy? Yes, but limited. Safe? Current thinking is that up to 5 days can

be recommended, and doses limited (1-2g daily, in divided doses)

Concerns about possible mutagenicity, but no clinical evidence in support

Some authorities suggest only up to normal food levels (approx 1g daily)

Childbirth – is Raspberry leaf (Rubus idaeus) useful?

Contains: flavonoids, unknown actives Raspberry leaf widely available Evidence for efficacy? Very limited – conflicting

reports from 2 Australian studies But how do you measure it?! Pharmacological studies show weak uterotonic

effect Safety???

Herbs used in lactation

No clinical evidence for any, but traditional usage by herbalists widespread for all

For shatavari (Asparagus racemosus) some pharmacological studies in rats and er… buffaloes - showed increase in milk flow

Remember constituents may pass into breast milk

Varicose veins and ‘heavy legs’: saponin-containing herbs

Horse Chestnut (Aesculus hippocastanum) and Butcher’s Broom (Ruscus aculeatus), both used internally and externally

Evidence: good! (Internal use in pregnancy not recommended due to absence of research, but a small study of horse-chestnut reported no adverse events after 2 weeks)

Safety: no clinical reports of toxicity

Varicose veins: flavonoid and anthocyanin-containing herbs

Red Vine (Vitis vinifera)– leaf extract, both internally and externally. Contains flavonoids and anthocyanins. Evidence: reasonable –several clinical studies to support

Bilberry, hawthorn, ginkgo: little evidence in varicose veins, but some rationale for use

Safety: no reports as yet of interactions Internal use in pregnancy not recommended due to

absence of research

Memory enhancement

Evidence available for ginkgo (Ginkgo biloba), soya (Glycine max), ginseng (Panax ginseng) in menopausal women – but the extent of their usefulness is not yet established

May be related to various types of activity – e.g. oestrogenicity, increase in cerebral blood flow, stimulant effects etc

Weight loss

No clinical evidence for any, except ephedra, (Ephedra sinica, Ma Huang)

Contains ephedrine, a sympathomimetic (amphetamine-like) biogenic amine

Banned in the US Responsible for some deaths Detox mixtures usually diuretic herbs with extra

nutrients or minerals

Relevant herb-drug interactions 1

Agnus castus: theoretical possibility of interacting with dopaminergic receptors

Bilberry – none reported, none expected Boldo: report (unproven) of interaction with warfarin Butcher’s Broom: none reported Dong quai: 1 case with warfarin (reduced prothrombin

time) Evening Primrose oil: inhibits CYP3A4, 1A2, 2C9, 2D6

and 2C19 in vitro – however, similar fatty acids are common in many foods

Ginger: inhibits CYP3A4, 1A2, 2C9 and 2D9 in vitro – but no clinical reports

Relevant herb-drug interactions 2

Ginseng: conflicting reports on CYP enzymes; weak inhibition of P-glycoprotein; avoid with MAOIs, warfarin, nifedipine and cancer chemotherapy

Horse chestnut: none reported Raspberry leaf: none reported Red Vine: none reported St John’s wort: oral contraceptives, Sage: none reported Soya: conflicting reports, but avoid with oestrogens and

anti-oestrogens for obvious reasons

Conclusions

Women are very likely to take herbal medicines Only a few are well researched (see previous

presentations) Some are effective, some not Most appear to be safe The interaction profile of most is favourable –

although St John’s wort has the usual caveats Unfortunately slimming herbs don’t work!

Reference sources

Principles and practice of Phytotherapy. Mills S and Bone K, Churchill Livingstone, UK, 2000

Potter's Cyclopedia of Herbal Medicines, E M Williamson, C W Daniels, UK. 2003

Interactions between Herbal and Conventional Medicines. E M Williamson (2005) Expert Opinion in Drug Safety 4 (2) 355-378

Major Herbs of Ayurveda. Dabur Research Foundation. Ed: E M Williamson; Elsevier 2002

Herbal Medicines 2nd Edition. Barnes, Anderson and Phillipson. Pharmaceutical Press 2002

Natural Standard Herb and Supplement Reference.Evidence-Based Clinical Reviews. Mosby 2005